Yamaha YZF-R125 Owners Manual: Ignition circuit cut-off system

The ignition circuit cut-off system (comprising the sidestand switch, clutch switch and neutral switch) has the following functions.

  • It prevents starting when the transmission is in gear and the sidestand is up, but the clutch lever is not pulled.
  • It prevents starting when the transmission is in gear and the clutch lever is pulled, but the sidestand is still down.
  • It cuts the running engine when the transmission is in gear and the sidestand is moved down.

Periodically check the operation of the ignition circuit cut-off system according to the following procedure.


WARNING
If a malfunction is noted, have a Yamaha dealer check the system before riding.

    Sidestand
    The sidestand is located on the left side of the frame. Raise the sidestand or lower it with your foot while holding the vehicle upright. TIP The built-in sidestand switch is part of the ign ...

    For your safety - pre-operation checks
    Inspect your vehicle each time you use it to make sure the vehicle is in safe operating condition. Always follow the inspection and maintenance procedures and schedules described in the Owner's Ma ...

    Other materials:

    Checking the ignition timing
    NOTE: Prior to checking the ignition timing, check the wiring connections of the entire ignition system. Make sure all connections are tight and free of corrosion. 1. Remove: Rider seat Left lower side cowling Refer to "GENERAL CHASSIS" on page 4-1. 2. Remove: Timing mark acces ...

    Troubleshooting
    The ignition system fails to operate (no spark or intermittent spark). NOTE: Before troubleshooting, remove the following part(s): 1. Seats 2. Fuel tank 3. Right side cover 4. Left side panel 5. Left upper side cowling ...

    Checking the piston pin
    1. Check: Piston pin Blue discoloration/grooves  Replace the piston pin and then check the lubrication system. 2. Measure: Piston pin outside diameter "a" Out of specification Replace the piston pin. 3. Measure: Piston pin bore diameter "b" Out of specifica ...

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